linux-kernel - Re: [testcase] perf: yet another fuzzer triggered crash

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 1 Jul 2013 11:07:13 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Vince Weaver <vincent.weaver@...ne.edu>
Cc:	linux-kernel@...r.kernel.org, Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	trinity@...r.kernel.org
Subject: Re: [testcase] perf: yet another fuzzer triggered crash

On Fri, Jun 28, 2013 at 05:07:38PM -0400, Vince Weaver wrote:
> On Fri, 28 Jun 2013, Vince Weaver wrote:
> 
> > On Fri, 14 Jun 2013, Vince Weaver wrote:
> >  
> > > OK, I haven't managed to get a small reproducible test case for the system 
> > > crash yet
> > 
> > I wasted the last 2 days bisecting a 10000 syscall trace, but below is a 
> > 20-syscall testcase that rapidly makes a core2 machine running 3.10-rc7 
> > unusable.
> 
> and it turns out I might have bisected down too much, as though that 
> crashes my core2 system it doesn't crash newer machines.
> 
> I'm too lazy to re-bisect today, but the much longer program here:
>    http://web.eece.maine.edu/~vweaver/files/nmi_bug_snb.c
> reliably causes the same crash on a Sandybridge machine I have running 3.9

OK, so on my westmere it triggers that WARN in task_ctx_sched_out() a
_lot_ (I removed the ONCE for easier debugging earlier -- still kinda
stumped there).

Then this thing causes an RCU stall and starts triggering NMI watchdog
msgs.. so YAY! :-)

I'll see what I can find.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/